I’m glad you brought up Maslows Hierarchy of Needs. The significance of free will becomes acutely apparent when contrasting our basic needs (breathing, shitting, sleeping, eating, ect.) with our higher hopes and aspirations (morality, creativity, self esteem, achievement, friendship, respect by and for others, etc.). The higher up Maslow’s Hierarchy of Needs you go the more prevalent and integral the significance of free will proves itself to be. At the bottom of the Hierarchy personal agency carries little significance… nobody feels a sense of accomplishment for something as rudimentary as breathing. Maintaining the fortitude to act morally, though, is an entirely different story. With breathing my autonomic nervous system completely takes over (unless I try to control my breathing through meditation or need to hold my breath because I’m under water or something), but I don’t feel any more of a personal connection to it than I do to the wind that blows outside of my window. With breathing air or digesting food my body is just a conduit for forces that flow through me – with morality or achievement I am far less removed… I am a fully present agent that acts upon the world instead of being merely acted upon. It is simply undeniable that our sense of self and the capacity for genuine freedom is of great importance to our higher needs. The superficial pleasure one gets out of eating a doughnut or a lifetime of successful urinating is qualitatively different than, say, the joy one feels after having saved a drowning child, earning a college degree, or experiencing a loving and respectful relationship with another.
“There is no important difference in true or false moral responsibility, because the results will still be the same in a world that is deterministic.” For an entirely unreflective person this might be the case, but for anyone who allows this issue its proper weight and truly understands what’s at stake, well… it makes all the difference in the world. For those that earnestly seek truth - the way things actually are is, at least, as important as how things seem. And if determinism happened to be the way things actually were then that very “fact” would cast an ominous shadow. Just because a person wouldn’t (and couldn’t) keep the concept of determinism constantly in the forefront of their thoughts every single moment of every single day doesn’t mean it would have no impact. A person’s happiness can be damaged through the knowledge that their spouse cheated on them or that a loved one died… through the lens of a deterministic interpretation the “knowledge” that we live in a universe governed by mechanical inevitabilities and that life is a pointless charade would be utterly earth shattering.